The setup: General widespread snow associated with a deep Low will continue throughout this Christmas Eve. We’ll likely see another couple inches of accumulation in spots out of that. However, Santa will have a bumpy ride making his final stops early on Christmas Day, as Lake Erie will spawn a response of its own in the morning hours of Monday, in terms of a localized lake effect snow band….and it could be significant.

Models have been in agreement that a sharp and well-defined lake snow band will come together off Lake Erie and impact portions of Western New York. Healthy winds off the lake will likely direct the heaviest portion of the band towards the Southern Tier, with likely snowfall rates approaching to potentially exceeding, three inches per hour, allowing for some pretty weighty accumulations.

While the most intense timing of this event will be late tonight, through Tuesday evening, lake snow looks to last through, at least, Wednesday afternoon. However, forecasting of the remaining lake snow is still in limbo, as support moisture appears to decrease, as the event starts to wind down. Nonetheless, there does appear to be enough unstableness in the atmosphere and strong thermal troughing (a region of cooler-than-average temperatures) over the Great Lakes, to allow lake snow to continue in lighter pockets through midweek.

Will I Need My Shovel, Snowblower, Or Plow?: Plow for some, Snowblower for some others. Accumulations will vary depending on your location, and where the most intense part of the lake band tends to hover. In terms of accumulation, were likely looking at two to three feet in some parts of the Southern Tier. The “Snow Machine” algorithm in our in-house VIPIRCast computer forecast model is spitting out more conservative totals, compared to the output of some other computer models, but three feet of fresh lake effect is not totally out of the question.